Motor vehicle window assemblies typically have one or more sliding panes, that is, panes which slide from a closed position to a full open position, and which may be either manually operated or operated by an electric motor. Such window assemblies are used, for example, as rear slider windows for pickup truck cabs to increase airflow into the motor vehicle. Typically such rear slider windows have a circumferential (that is, outer peripheral) frame in which the sliding pane is mounted along with one or more fixed panes. The frame may be structural or semi-structural in that it integrates the sliding pane and one or more fixed panes as a self-contained preassembled module suitable for shipping and handling prior to installation into a motor vehicle.
Sliding window assemblies are increasingly popular, particularly when used for backlights in pickup trucks. A power window assembly for a vehicle having a sliding pane is shown in U.S. Pat. No. 5,724,769 to Cripe et al. Cripe et al is a robust design for a pull-pull power sliding window assembly having left and right fixed panes and a horizontally sliding center pane sliding between upper and lower run channels. A drive motor, drive drum and drive cable pull the sliding pane back and forth in a manner similar to conventional cable drum window regulators. Cable directional blocks route drive cable from below the frame to a lower horizontal peripheral edge of the sliding pane. Such a design advantageously routes the cables so as to avoid excessive drag associated with pulling the sliding pane up against the upper run channel or down against the lower run channel.
While such a design is excellent for reducing friction and thereby minimizing wear and tear, it has been found increasingly desirable to maximize a central air opening created when the sliding pane moves to the full open position. The size of the opening created in a horizontally sliding window module such as that disclosed in Cripe et al is necessarily limited by not only the size of the sliding pane but also by the requirement that the sliding pane slide back and forth within the frame of the module. Thus, the length of the run channels, the size of the fixed panes, and the overall size of the modular window assembley all act to limit the maximum available size of the air opening when the sliding pane moves to the full open position. It would be desirable to provide a sliding window assembly where the air opening produced when the sliding pane moves to the full open position is increased beyond that available with conventional horizontally sliding panes positioned in a sliding window module.
In view of the foregoing, it is an object of the present invention to provide a sliding window assembly having a central opening can be closed by a sliding pane where the central opening is significantly larger than central openings in traditional horizontally sliding window assemblies.
It is an additional object of at least certain preferred embodiments of the present invention to provide a sliding window assembly for a motor vehicle having attractive exterior styling while preserving structural integrity of the motor vehicle. It is another related object of the present invention to provide a sliding window assembly that is highly reliable in operation. Additional objects and optional features of the invention will be apparent form the following disclosure and detailed discussion of preferred embodiments.